Device for cutting a continuous strip of paper

ABSTRACT

This device for cutting a continuous strip of paper into sections of same predetermined length comprises cutting members or knives mounted on a rotary holder or carrier and adapted to cut the strip of paper travelling against the registering surface of a counter-drum also driven for rotation. This rotary drum on which the strip of paper is caused to travel comprises spaced cutting inserts so mounted thereon that the knife edges engage the relevant inserts only during the paper cutting operation, said inserts setting themselves automatically in parallel relationship to said knives. This device may be used notably in cigarette making machines for preparing the filter-plugs of the cigarettes.

[ June 24, 1975 United States Patent [1 1 Yerjux DEVICE FOR CUTTING A CONTINUOUS Primary Examiner-4. M. Meister Attorney,

STRIP OF PAPER Inventor:

Jean verjux, Pavillons Sous B Ois, Agent, or FzrmAmster & Rothsteln France ABSTRACT Usines Decoufle, Paris, France [73] Assignee:

This device for cutting a continuous strip of paper into f same predetermined length comprises cutting members or knives mounted on a rotary holder or carrier and adapted to cut the strip of paper travelling the registering surface of a counter-drum also driven for rotation.

a F p FA paper is caused comprises spaced cutting inserts so mounted thereon that the knife edges engage the relevant inserts only during the paper cutting operation, said y in parallel f m 0 p a .m m s m u .m a t h S .w Wm h .1 w an n mk 0 mm m a mom y m.m r eh a] SS 0V S a .w .mu mm h sl Tm .mm m 92 4 3 find 6 /5 %2 3 7 M4H B2 3 3 y. u4 3 m 8 i. n 6 m 4 n l m B my n 3 m 8 we a C u. n u" a nu r uh K N mmw W mmS h 2 010 J b Le e .I F U.| .F Hum 555 This device may be used notably machines for preparing the in cigarette making filter-plugs of the [5 6] References Cited UNITED STATES PATENTS s e r u g F g n w a r D 3 S h C 5 em m e r a .W C 0066 444 333 333 000000 wnn mm mm ce O0 MDD 759 066 999 111 //l 202 sum PATENTEDJUN24 ms DEVICE FOR CUTTING A CONTINUOUS STRIP OF PAPER FIELD OFTHE INVENTION The present invention relates-to means for cutting a continuous strip of paper into sections havingthe same, predetermined length, and has particular reference to a device of this type which comprises elements or knives mounted on'a rotary support and adapted to cut a strip of paper travelling' 'continuously against the surface of a likewise rotary counteror pressure drum.

In devices of this type a clean cut cannot be obtained unless the knife engages the drum surface with a sufficient, relatively high pressure, and more particularly unless this pressure be equally distributed throughout the paper width.

DESCRIPTION OF THE PRIOR ART Devices of this character are already known wherein the cutter knives are so mounted that their cutting edges set themselves automatically in a position parallel to the drum surface portion with which they are brought into engagement during the cutting phase.

SUMMARY OF THE INVENTION According to the present invention,'the rotary drum on which the strip of paper is caused to travel comprises spaced cutting inserts so mounted that the cutting edges of the knives engage said inserts during the cutting operation, said cutting inserts setting themselves automatically parallel to said cutting edges.

On the other hand, the knife holder or carrier is so mounted that it can yield slightly to absorb the moderate penetration of the cutting edges of the knives into the registering cutting inserts, this penetration being necessary in order to obtain a clean cut.

BRIEF DESCRIPTION OF THE DRAWING Other features of this invention will appear as the following description proceeds with reference to the accompanying drawing illustrating diagrammatically a typical form of embodiment of the device constituting the subject-matter thereof. In the drawing:

FIG. 1 is an end view with parts shown in section;

FIG. 2 is a front elevational view with parts broken away and vertical sections; and

FIG. 3 is a section taken along the line IIIIII of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT The device illustrated comprises a central core 1 having lateral shaft extensions 2 and 3. This central core 1 has formed therein a number of spaced notches 4 parallel to the axis of said shaft extensions; in the example illustrated, six notches 4 are provided. Each notch 4 has fitted therein a square-sectioned cutting bar 5 retained by a pair of plates 6 and 7.

The length and diameter of said shaft extensions 2 and 3 are dimensioned to afford a slight yielding movement of the assembly when the projecting edge of each cutting bar 5 engages the registering counter-drum.

The outer ends of said shaft extensions are journalled in brackets or like supports 8 and 9 by means of ballbearings 10 and 11 preferably of the self-aligning type, as shown. The cutter holder or carrier is rotatably driven by suitable means (not shown) engaging for ex- "13 having disposed on its outer periphery two rows of elements 14,-: for instance between lateral retaining disks, as shown. Each element 14 carries a pivot pin 15 and a pair of cylindrical lateral studs 16 and 17 parallel to said pin 15. A cutting insert 18 has a semi-cylindrical notch formed therein for engagement with the pivot pin 15 and *comprises a pair of circular holes in which the studs 16 and 17 are fitted; the diameter of these holes is slightly greater than that of said studs so that the cutting insert 18 can pivot about the axis of pin 15. The counter-drum further comprises a central bore adapted to receive a shaft 19 for driving said drum at the proper speed.

The device thus constructed operates as follows:

A continuous strip of paper 20 is fed to the drum 12 by suitable feed means 21. The linear velocity imparted to said strip by the feed means 21 is slightly inferior to the peripheral velocity of drum 12 and consistent with the velocity of rotation of the cutter carrier or holder; as will be readily understood, this strip velocity is such that it will deliver the desired paper length for each element or section to be cut.

The paper is retained on the drum 12 by pneumatic suction through ports (not shown) opening through the outer periphery of said elements 14. Thus, the paper is driven by the drum while slipping thereon, but when a paper section is cut it travels at the peripheral speed of the drum so as to create a gap between successive cut elements or sections as shown in FIG. 2.

According to the thickness of the strip of paper to be cut, the knife edges 5 must be set to a radius OA variable but in any case slightly greater than the distance OB (FIG. 1) to the outer surface of the counter-drum. This slight penetration is absorbed by a minimum flexion of shaft extensions 2 and 3.

On the other hand, in case the axes of the knife carrier and drum were not exactly parallel, the cutting insert 18 will pivot about the pivot pin 15 to accommodate this misalignment and cause the outer surface of the insert 18 to be exactly parallel to the cutting edge of cutting bar 5. In other words, the outer surface of insert 18 will engage the edge of cutter bar 5 throughout the width of this edge, thus producing a clean cut of the successive paper sections.

The knife holder and counter-drum rotate at the same peripheral velocity and the peripheral pitches of the knives carried by said knife holder and of the cutting inserts carried by the drum are equal.

Of course, various modifications may be brought to the specific form of embodiment illustrated and described herein, without departing from the basic principle of the invention as set forth in the appended claims. Thus, the numbers of notches formed in the core 1 and in the drum for receiving the cutting knives and inserts, respectively, may differ from those shown by way of illustration, and the relative dimensions of said core and drum are also optional.

What is claimed is:

1. Device for cutting a continuous strip of paper into sections having the same predetermined length, which comprises cutting elements mounted on a rotary holder adapted to cut a strip of paper travelling continuously against the surface of a likewise rotary counter-drum, spaced cutting inserts so mounted that the cutting elements engage a registering insert when cutting the strip of paper, a plurality of pins corresponding to said iiiserts mounted respectively in said counter-drum to extend in a direction parallel to the peripheral tangent of said counter-drum, each of said cutting inserts being mounted to pivot on one of said pins during the operation of the device.

2. Device according to claim 1, characterized in that each of said cutting inserts bears by means of a semicircular notchvformed in its lower face against said pivot pin.

3. Device according to claim 2, characterized in that each of the cutting inserts has formed therein a pair of lateral holes with a certain play on a pair of studs spaced from and extending parallel to said pivot pin.

cry of said drum. 

1. Device for cutting a continuous strip of paper into sections having the same predetermined length, which comprises cutting elements mounted on a rotary holder adapted to cut a strip of paper travelling continuously against the surface of a likewise rotary counter-drum, spaced cutting inserts so mounted that the cutting elements engage a registering insert when cutting the strip of paper, a plurality of pins corresponding to said inserts mounted respectively in said counter-drum to extend in a direction parallel to the peripheral tangent of said counterdrum, each of said cutting inserts being mounted to pivot on one of said pins during the operation of the device.
 2. Device According to claim 1, characterized in that each of said cutting inserts bears by means of a semi-circular notch formed in its lower face against said pivot pin.
 3. Device according to claim 2, characterized in that each of the cutting inserts has formed therein a pair of lateral holes with a certain play on a pair of studs spaced from and extending parallel to said pivot pin.
 4. Device according to claim 3, characterized in that said drum comprises a central body having spaced elements mounted on its outer periphery, each of said pivot pins engaged within one of said cutting inserts projecting from a front face of said element.
 5. Device according to claim 3, characterized in that the studs engaged with play by the lateral holes of said cutting inserts project from the front surface of the elements mounted at spaced intervals on the outer periphery of said drum. 